Electrical utility firms such as those constructing, operating or maintaining overhead and/or underground power distribution networks utilize connectors to tap main power transmission conductors and feed electrical power to distribution line conductors, sometimes referred to as tap conductors. The main power line conductors and the tap conductors are typically high voltage conductors that are relatively large in diameter and the main power line conductor may be differently sized from the tap conductor. As a result, specially designed connector components are often needed to adequately connect tap conductors to main power line conductors. Generally, three types of connectors are commonly used for such purposes: bolt-on connectors, compression-type connectors, and wedge connectors.
In the installation and removal of electrical connectors, hot stick tools reduce risk of shock and help access connectors that are difficult to reach. A hot stick tool includes a pole and a tool for adjusting a connector. The pole is an insulated pole, usually made of fiberglass or another insulated material. In addition to providing electrical insulation for the individual, the pole provides physical separation from the power lines. The physical separation reduces the chance of burns that could result from electrical arcing that may occur due to a malfunction of the power lines. The tools include mechanical systems, hydraulic systems, and pneumatic impact tools.
Generally, bolt-on connectors require a specific tool permitting the bolt to be adjusted from a safe distance. Compression connectors require a specific tool allowing for the necessary deformation of the connector. Wedge connectors often require a specific tool permitting the use of explosive cartridges packed with gunpowder to drive the wedge member of the wedge connectors into C-shaped members.
Bolt-on connectors, sometimes referred to as clam shell connectors, typically employ die-cast metal connector pieces or connector halves formed as mirror images of one another. Each of the connector halves defines opposing channels that axially receive the main power conductor and the tap conductor, respectively, and the connector halves are bolted to one another to clamp the metal connector pieces to the conductors. Bolt-on connectors have been widely accepted in the industry primarily due to their ease of installation, but such connectors are not without disadvantages. For example, proper installation of such connectors is often dependent upon predetermined torque requirements of the bolt connection to achieve adequate connectivity of the main and tap conductors. Applied torque in tightening the bolted connection generates tensile force in the bolt that, in turn, creates normal force on the conductors between the connector halves.
Compression connectors may include a single metal piece connector that is bent or deformed around the main power conductor and the tap conductor to clamp them to one another. Such compression connectors are generally available at a lower cost than bolt-on connectors, but are more difficult to install. Hand tools are often utilized to bend the connector around the conductors. In addition, because the quality of the connection is dependent upon the relative strength and skill of the installer, widely varying quality of connections may result.
Wedge connectors include a C-shaped channel member that hooks over the main power conductor and the tap conductor. Wedge connectors also include a wedge member having channels on opposing sides configured to be driven through the C-shaped member, deflecting the ends of the C-shaped member and clamping the conductors between the channels in the wedge member at the ends of the C-shaped member. Such connectors tend to be more expensive than either bolt-on or compression connectors, but are generally believed to provide superior performance over bolt-on and compression connectors. For example, such connectors include a wiping contact surface that, unlike bolt-on and compression connectors, is stable, repeatable, and consistently applied to the conductors, and the quality of the mechanical and electrical connection is not as dependent on torque requirements and/or relative skill of the installer.
U.S. Pat. No. 7,309,263 (the '263 patent), which is herein incorporated by reference but not intended as limiting, discloses an assembly comprising a first conductive member comprising a first hook portion and a first base wedge portion, the first hook portion extending from the first wedge portion and adapted to engage a first conductor. A second conductive member is also disclosed that comprises a hook portion and a wedge portion; the hook portion extending from the wedge portion and adapted to engage a second conductor. The wedge portion of the first conductive member and the wedge portion of the second conductive member disclosed in the '263 patent are adapted to nest with one another and be secured to one another. The assembly disclosed in the '263 patent further comprises a displacement stop that is located on at least one of the first and second conductive members. The displacement stop is positioned to define a final displacement relation between the first and second conductive members once fully mated. The displacement stop defines a final mating position between the first and second conductive members independent of an amount of force induced upon the first and second conductors by the first and second conductive members.
The style of electrical connector disclosed in the '263 patent cannot easily be installed using any existing hot stick tool due to the differences between it and more traditional bolt-on connectors, compression-type connectors and wedge connectors. In addition, newer connectors, such as those disclosed in the '263 patent, include features of each of the bolt-on connectors and wedge connectors. Existing hot stick tools are not able to adequately accommodate such a combination of features. While installing such electrical connectors by other means, such as wearing rubber or insulated gloves, is possible, such methods frequently are not permitted based upon local law and/or labor contracts.
Therefore, there is an unmet need to provide a hot stick tool capable of being used for installation of certain types of electrical connectors.